The flushSync function in React is used to flush updates synchronously. It schedules updates to be performed inside a high-priority task, ensuring that the updates are executed immediately and synchronously before returning control to the caller.
import { flushSync } from 'react-dom';
flushSync(callback);This is useful in situations where you need the DOM to be updated immediately, such as for measurements or to ensure synchronous rendering. However, excessive use of flushSync can lead to degraded performance, so it should be used judiciously.